The Rumormongers are people who, through whatever means, have developed a common affinity for picking up rumors, and a system in which they "receive" information on any rumor and contribute with a rumor of their own in exchange. Most of the information they receive is part of the weirdness populating Sumaru City and the development of the Masked Circle/New World Order's plans, and in exchange they divulge information about the "hidden side" of Sumaru (secret content which may be unlocked), which can be made true by visiting the Kuzunoha Detective Agency and having the rumor scattered in exchange for a non-fixed fee.

Some of the Rumormongers' rumors may conflict or outright contradict each other; when this happens, it is the party's chance to select which version will be made real at the Detective Agency. Information the Rumormongers varies from stores now carrying armor and weaponry among their wares, to entire locales made available for visit, such as Mu Continent.

While the Rumormongers are the party's main source of rumors, they are by no means the only ones: several people across Sumaru will pitch in rumors.